BioThrax(r) is the only FDA-approved anthrax vaccine and is currently indicated for use in the pre-exposure setting for individuals at high risk of exposure to Bacillus anthracis spores. Five million doses of the vaccine have been purchased for the Strategic National Stockpile. The most likely use of these doses is for postexposure prophylaxis (PEP) in the event of an anthrax attack. BioThrax(r) is not currently licensed for this indication, however, the use of the vaccine in this scenario is likely to enable a shortened course of antimicrobial therapy, which can lower antimicrobial-associated adverse events, and to reduce morbidity and mortality. As part of studies to obtain FDA approval of BioThrax(r) for the indication of PEP, EIS will conduct a clinical trial to identify an optimized BioThrax(r) schedule that quickly elicits and maintains an immune correlate of protection; the immune correlate will be derived from rabbit and nonhuman primate efficacy studies according to the "Animal Rule." This phase 3b clinical trial, Safety, Immunogenicity, and Immunization Schedule Study of Post-Exposure Prophylaxis for BioThrax(r) in a Population of Healthy Adults, will evaluate the safety and immunogenicity of four BioThrax schedules. This trial is designed to establish an optimal vaccination schedule for PEP, primarily to minimize the time to achieve protective immunity, and secondarily to maximize the duration of protective immunity with the least number of vaccinations. The Specific Aims of the clinical trial planning are to: 1) Develop study-related documents and procedures; 2) Establish data management structure; 3) Train study personnel on study-related documents and procedures; 4) Ratify vendor contracts and investigator agreements; 5) Obtain Investigational Review Board (IRB) and/or Office of Human Subjects Protection (OHRP) approval; and 6) Obtain Investigational New Drug Application (IND) approval. These aims will be accomplished by study planning committees staffed with individuals with all the necessary expertise: Scientific Review, Regulatory Affairs, Data Management, Pharmacovigilance, Study Management, Study Monitoring, Quality Assurance and Legal affairs. The Principal Investigator has oversight over each committee and has assigned each: a mission, a chairperson, membership, key deliverables, and target completion dates. A BLA amendment for the licensed use of BioThrax(r) in the post-exposure setting of an anthrax attack would facilitate mass vaccination and potentially decrease the duration and reliance on antibiotics and improve survival rates. Emergent BioSolutions is a biologics company focused on the research, development and manufacture of novel vaccines and related products for prophylactic and therapeutic use against common diseases and biological weapons of mass destruction. Its subsidiaries are BioPort Corporation, the primary manufacturing operation, headquartered in Lansing, Michigan; research-focused Emergent ImmunoSolutions, located in Gaithersburg, Maryland; and research focused Emergent Europe Limited, located in Reading, England. [unreadable] [unreadable] [unreadable]